GB1384453A - Artificial joints - Google Patents

Abstract

1384453 Artificial joints E G FINDLAY 23 Feb 1973 [4 March 1972] 10207/72 Heading A5R A prosthetic joint comprises first and second members 10, 16 respectively, adapted to be rigidly connected to respective bones, wherein a ball 11 on the member 10 locates in a socket 18 of the member 16, which socket 18 extends over more than a half-sphere so as to resist dislocation of the joint following snapengagement of the ball 11 in the socket 18, the ball 11 having a pair of diametrically extending trunnions 15 which are received in corresponding recesses in the socket 18 for limiting relative angular movement of the members 10, 16 in at least one plane. The member 10 is formed from titanium, a cobalt/ chromium/molybdenum alloy or stainless steel and includes a spike 12 and a shield 14 extending from the spike 12. The trunnions 15 may be integrally formed on the ball 11 or may be formed by a cylindrical nut and bolt extending through a bore in the ball 11. The shield 14 locates behind the patella and has a fluted part 14a for accommodating ligaments. The member 16 is made from high density polyethylene or polyester and includes a frusto-conical part 17, a flange 21 and a shank 22. A rim 19 defines the socket 18, the U-section recesses (20), Fig. 5, (not shown) accommodate the pins 15 and allow large angular movements of the shank 22 and the spike 12 in only one plane, and a recess (30) accommodates the spike 12 to allow the joint to take up a kneeling position. The shank 22 is fluted and the flange 21 has grooves 23 to allow flow of cement during installation. The spike 12 is located in the femur and the shank 22 in the tibia but the joint may be used for other parts of the body.